My Saratoga website isn't WAN accessible (without firewall modifications as I can access my network from the WAN) but I put 7.0.1 on the Pi I'm running the webserver on and it seems ok. I don't access it a lot, but the only deprecated message I could find was related to Cumulus server side graphs and having to change jpgraphs to 4.0.2 in order for it to work. 3.5.1 won't work on PHP7 as far as I can tell.

I'm running PHP Version 7.0.14 on saratoga-weather.org and all the current release (stock) scripts are working fine with no errors. Some 3-rd party scripts may need updates which would be provided by those authors. The USA nws-alerts.php script does need a couple of variable initialization tweaks (to initialize as array() instead of '' (a null string)). PHP 7.1 stops doing auto-recasting of string-to-array and posts warning messages instead.

I'll be testing with PHP 7.1 a bit later when I have it available on my VPS.

Just upgraded the development webserver from Wampserver v3.06 to v3.08 which was required to install PHP v7.1.1Unfortunately PHP v7.1.1 has the same issue as PHP v7.1.0 with the one webpage mentioned before. Everything else appeared OK.Pretty sure this relates to the array changes in v7.1.xAlso installed the just released PHP v7.0.15 - it is amazing to see how many bugs they are still fixing in 7.0

v7.0.15 appears OK as the same webpage that does not work in 7.1.x is fine in 7.0.15.